Note: Descriptions are shown in the official language in which they were submitted.
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Tobacco Slab
The present invention relates to a tobacco slab, a
process for making such tobacco slab and a package comprising
such tobacco slab.
Pre-formed pieces of tobacco are known in the art. For
example, US-A-1,365,969 discloses a plug of tobacco for
chewing or pipe smoking. The plug is composed of a densely
compacted filler of 'long-cut' tobacco enclosed in leaf
tobacco wrapper. For use, sections or slices of tobacco are
broken or cut off from the plug and manually brought into a
sufficiently 'fluffy' condition suited for chewing or
smoking. A disadvantage of the disclosed tobacco plug is that
the tobacco is very densely compressed and requires manual
manipulation before use.
EP-A-0 647 411 discloses a tobacco cuboid made of
several pre-defined sub-portions. The tobacco cuboid is for a
smoker's use to make his own cigarettes. The individual sub-
portions are separated either by mechanical means, for
example by cuts or grooves, or by separating webs made of a
non-smokable material. The cuboid is made from a tobacco
strand which is then cut into partial strands corresponding
to the sub-portions. The coherence among the sub-portions is
problematical.
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DE-A-10346649 discloses tobacco portions made from a non-
woven fabric containing at least 50 percent of tobacco. The
non-woven fabric is a coherent, self-supporting web.
There is an increasing trend among smokers towards roll-
your-own and make-your-own cigarettes. Roll-your-own
cigarettes are made using fine cut tobacco which has a
density in the range of about 60 mg/cm3 and is typically sold
in reclosable, flexible plastic pouches. One of the
disadvantages of the roll-your-own method is that it allows
lo for cigarettes of variable tar and nicotine content. Make-
your-own methods aim at overcoming this disadvantage by
relying on pre-made or pre-defined tobacco portions which are
transferred into pre-made tubes of cigarette paper, typically
with a filter.
It is an object of the present invention to provide an
improved tobacco material which can be used by a smoker to
make his own cigarettes.
The present invention provides a continuous slab of
smokable tobacco with a substantially uniform composition and
distribution of shredded tobacco throughout the slab. In
particular, the present invention provides a tobacco slab
made of shredded tobacco characterized in that it is
continuous and has a substantially uniform composition and a
substantially uniform distribution of the shredded tobacco.
As used herein, shredded tobacco includes cut tobacco. The
tobacco slab of the invention enables the consumer to make
his own cigarettes of consistent quality and smoking
behavior.
The tobacco slab of the invention is obtainable by a
process comprising the steps of filling a pre-defined amount
of shredded tobacco into a suitable mold, evenly distributing
the shredded tobacco in the mold and evenly compressing the
shredded tobacco. Preferably, such process further comprises
the steps of removing the slab from the mold and transferring
the slab into a package.
The slab according to the present invention is a
continuous tobacco slab. The slab lacks any means or
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indications of pre-portioning or separation. In particular,
the slab is devoid of any mechanical or physical means
creating pre-portions, such as, for example, grooves, cuts or
separating webs.
The tobacco slab according to the present invention is
composed of shredded tobacco, preferably in cut filler form,
for example blended, cased, cut and flavored tobacco.
Preferably, the slab has a thickness of between about 6 mm
and about 12 mm. The slab has a substantially uniform and
lo homogeneous composition. This facilitates the production of a
uniform batch of self-made cigarettes with substantially
consistent quality and smoking behavior under identical
conditions.
The tobacco slab may comprise any desired quantity of
shredded tobacco sufficient to make at least two cigarettes.
Preferably, the tobacco slab of the invention comprises at
least about 3.5 g of cut filler, more preferably at least
about 15 g of cut filler, most preferably between about 15 g
and about 50 g of cut filler, which amount is evenly
distributed across and throughout the slab. If desired, the
cut filler may comprise small amounts of one or more suitable
non-tobacco additives, for example suitable particulate
additives. Suitable additives are known in the art and have
been disclosed for incorporation in the cut filler used in
the tobacco rod of pre-manufactured cigarettes. Such
additives include, for example, additives, such as
nanoparticle additives, which during smoking of the cigarette
are capable of acting as oxidants for the conversion of
carbon monoxide to carbon dioxide or as catalysts for the
conversion of hydrocarbons, aldehydes, or phenolic compounds
to carbon dioxide and water.
The shredded tobacco is substantially uniformly
distributed across the slab. The tobacco density is a
function of tobacco weight and compression. As compared to
loose cut filler, the cut filler in the slab is moderately
compressed, that is the tobacco essentially retains its
natural flexibility and elasticity after compression.
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Preferably, the cut filler in the slab is uniformly
compressed by a factor of between about 2 and about 6, more
preferably by a factor between about 2 and about 4, most
preferably by a factor of between about 3 and about 4 as
compared to loose cut filler of the same composition. The
compression factor is essentially the same across and
throughout the cut filler. Preferably, the cut filler in the
slab has an average (filling) density between about 150
mg/cm3 and about 250 mg/cm3. The average filling density of
lo the slab is calculated as the quotient of weight per volume.
The person of ordinary skill in the art will readily
appreciate that the density will be affected by various
parameters, including for example the type or types of
tobacco and the amount of expanded tobacco employed in the
cut filler. Preferably, the tobacco slab of the present
invention has substantially the same firmness across the
slab.
The strand length or cutting width of the shredded
tobacco in the tobacco slab of the present invention is
relatively short and substantially the same as in
conventional pre-fabricated cigarettes, for example between
about 0.4 mm and about 0.9 mm. Preferably, the cutting width
of the cut filler is between about 0.6 mm and about 0.8 mm.
Preferably, the tobacco slab according to the present
invention does not include any outer or inner binding agent
such as, for example, combustible fibers like cellulose or
other natural materials woven into the tobacco, agar agar,
guar gum or cellulose pulp.
The continuous tobacco slab of the present invention is
H of pre-defined shape and size. Preferably, shape and size are
such that the slab yields at least two, preferably at least
five, more preferably between 20 and 40 cigarettes of a
standard length and diameter, for example conventional king
size. Typically, the dimensional parameters of the final
cigarette, and hence of the slab, will be determined by the
size of the commercially available, pre-manufactured
cigarette paper tubes. In particular, height and width of the
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slab are such that the consumer can readily make his own
cigarettes, for example conventional king size filter
cigarettes, relying on commercially available cigarette paper
tubes. To minimize or avoid tobacco waste, the width of the
5 slab essentially corresponds to the length of such tubes
(excluding the filter). If desired, the width of the slab may
slightly exceed the filling length of the tubes by up to
about 10 percent, or less. While the tobacco slab may be of
any shape, the shape should be such as to minimize waste in
lo use, for example on a cigarette making device. Preferably,
the slab has the shape of a rectangular parallelepiped with a
height of between about 6 mm and about 12 mm, preferably of
between about 8 mm and about 12 mm. Preferably, the slab
width is between about 65 mm and about 80 mm. The slab length
Is is not crucial and may vary depending on the number of
cigarettes the block is intended to yield. Advantageously,
the slab length is between about 75 mm and about 200 mm. The
maximum slab length may favorably be matched with the design
of the cigarette making device, which the smoker may use to
20 produce self made cigarettes using the tobacco slab of the
present invention. To avoid cigarettes with loose ends, the
tobacco slab does not flatten towards its edges.
If desired, the slab may be designed such that its height
or its cut filler density, or both, are slightly increased
25 along one or more pre-defined edges, preferably along the two
edges determining the slab width. The increased height and/or
density along at least one pre-defined edge may serve to
facilitate transfer of the slab, for example into the package
or, in particular, transfer into and through a cigarette
30 making device. Preferably, the density is suitably increased
along one side surface while the slab height is kept constant
across the slab.
In a preferred aspect, the present invention provides a
35 tobacco slab essentially consisting of shredded tobacco,
preferably in cut filler form. Preferably, the tobacco slab
has a density of between about 200 mg/cm3 and about 250
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mg/cm3, more preferably between about 220 mg/cm3 and about
240 mg/cm3. Advantageously, the total water content of the
slab is between about 12 and about 16 percent. Preferably,
the cut filler does not comprise any non-tobacco particulate
additives. Preferred is such tobacco slab consisting of cut
filler which slab has one or more of the features indicated
herein as being preferred.
Such tobacco slab may be made using a mold comprising a
bottom (or top) wall and four side walls. The plan of the
lo mold substantially corresponds to the plan of the tobacco
slab to be produced. Advantageously, mold length and width
are slightly smaller, for example less than a few millimeters
smaller, than width and length of the desired slab. The side
walls of the mold must be high (deep) enough so that the mold
Is can readily accommodate the chosen amount of loose cut
filler. For example, the mold should be about 4 to about 5
times higher, than the desired height of the slab. The mold
may be made of any suitable material, such as steel. To
facilitate removal of the slab from the mold, for example by
20 pushing, the mold is preferably made of or coated with a
material which does not stick to cut tobacco, for example a
suitable plastic material, and which is approved for use with
food. The mold is uniformly filled with the desired amount of
cut tobacco. Subsequently, the cut filler in the mold is
25 evenly compressed by application of a pre-determined external
pressure to yield a tobacco slab of pre-defined shape and
dimensions. The external pressure may be applied,
simultaneously or successively, to one or more surfaces of
the slab. Suitable compression tools and methods are readily
30 known in the art. For example, a pre-defined pressure may be
exerted by means of a rigid plate which may be moved
mechanically or pneumatically. Preferably, compression is
such that the height of the compressed slab is about 1 to 3
mm less than the desired final height of the slab.
35 Immediately after the pressure has been released the slab is
transferred into a suitable package as described herein
below. Preferably, this transfer involves sliding and/or
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pushing the slab by mechanical means. The transfer is
performed such that the geometrical shape and the integrity
of the tobacco slab including its density, uniformity and
distribution are substantially maintained. Advantageously,
the mold may have one or two removable side walls to
facilitate pushing and sliding the slab out of the mold.
Alternatively, the mold may have a bottom wall which can be
suitably raised or lowered to facilitate transfer of the slab
out of the mold. In the package, the slab may slightly expand
lo until it fills the available pack volume assuming its desired
final dimensions.
Alternatively to the above described sequential process,
the slabs according to the invention may also be made in a
continuous process, for example, by cutting slabs of the
desired size from a continuous strand.
The tobacco slab obtainable according to the process of
the invention is not a self-supporting non-woven fabric as
disclosed in DE-A-10346649. But the present invention
provides a tobacco slab made of shredded tobacco
characterized in that it is continuous and has a
substantially uniform composition and a substantially uniform
distribution of the shredded tobacco which slab is obtainable
by a process comprising the steps of filling a pre-defined
amount of shredded tobacco into a mold, evenly distributing
the shredded tobacco within the mold and evenly compressing
the shredded tobacco by exertion of a pre-defined pressure
and which slab excludes a self-supporting non-woven fabric.
The tobacco slab as provided herein is a non-self supporting
structure which looses its dimensional integrity and
stability without proper support. Means supporting the slab
are essential during its manufacture, transportation, storage
and handling. In particular, the slab has very little tensile
strength.
A method suitable to determine that a given slab is not
self-supporting and thus a tobacco slab according to the
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invention is a 'lifting test'. The test involves a tobacco
slab made of 23 g of cut filler having a width of 73 mm, a
height of 11 mm and a length 144 mm. The slab is carefully
removed from its package, transferred onto a flat support,
such as a table, and lifted with only two fingers. No other
supporting means for the slab is involved during the lifting.
For example, the slab may be taken up and lifted from a
supporting surface by partially or entirely covering the
right and left side surfaces (corresponding to the slab
lo width) with the index fingers of each hand. Alternatively,
the slab may be seized between the thumb and the index finger
of the same hand and lifted. On exposure to such test a non-
self-supporting tobacco slab according to the invention will
loose its dimensional integrity, that is it will break and
Is fall apart.
In another preferred aspect, the present invention
provides a multi-layer structure comprising a tobacco slab
according to the invention and in addition at least one
20 layer, preferably two layers, of another suitable smokable
material approved for use in cigarettes. For example, such
suitable smokable materials include paper made of natural
fibers, for example tobacco fibers, and reconstituted tobacco
sheet. A preferred material is top loaded reconstituted
25 tobacco sheet. Such material is known in the art and may be
made as described in WO-A-03/082030. Preferred is such
multi-layer structure comprising at least one layer of
another smokable material. Advantageously, such at least one
layer forms an outer surface of the multi-layer structure
30 providing for a relatively smooth outer surface of the
structure and reducing sliding friction and/or static
(sticking) friction as compared to the out surface of the
tobacco slab. Such layer thus facilitates transfer of the
structure, for example into or out of the pack.
35 Advantageously, the layer or layers self-adhere to the
tobacco slab without additive. The features of the slab
indicated above, in particular those described as preferred
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and in particular those of weight, width, length and average
density, also apply for such multi-layer structures. While
the multi-layer structure provided herein may or may not be
self-supporting, the tobacco slab component of such structure
is not self-supporting.
A preferred embodiment has a sandwich type, multilayer
structure, more preferably a three layer structure. Most
preferably, such three layer structure is a symmetrical
structure wherein the top layer is made of the same material
lo as the base layer. Particularly preferred is a tobacco
structure which is composed of a base layer of smokable
material (other than solely cut filler), a middle layer of
cut filler (i.e. of a tobacco slab according to the
invention) and a top layer of smokable material (other than
Is solely cut filler). Typically, the front, the back and the
side surfaces of the cut filler middle layer are not covered
or enclosed by the other smokable material used in another
layer of a multi-layer structure. Advantageously, the base
and top layers are each made of the same smokable material,
20 preferably reconstituted tobacco sheet, more preferably top
loaded reconstituted tobacco sheet. In the latter embodiment,
the cut filler top loads advantageously face towards the cut
filler middle layer. The top and base layers each have a
thickness of about 0.5 mm to about 2 mm while the cut filler
25 middle layer has a thickness of about 6 mm to about 10 mm.
Typically, the amount of reconstituted tobacco comprised
in the tobacco slab or the multi-layer structure according to
the invention (in sheet form and/or in the cut filler) is
limited. The total amount of reconstituted tobacco must not
30 exceed the upper limit as defined in the applicable
regulatory standard.
A multi-layer structure comprising the tobacco slab and
at least one layer, preferably two layers, of another
suitable smokable material may be produced using the tools
35 and methods as described above. For example, to produce a
three layer tobacco structure as described above the bottom
of a suitable mold, such as a mold as described above, is
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laid out with a sheet of reconstituted tobacco.
Advantageously, the size of the sheet is such that it covers
the entire surface of the mold bottom. Subsequently, the mold
is filled with a defined amount of cut filler as described
5 above. After covering the cut filler layer with another sheet
of reconstituted tobacco, a defined pressure is applied to
yield a tobacco structure with a compression factor and cut
filler density which is slightly higher than the compression
factor and density desired for the final multi-layer
lo structure.
In yet another aspect, the present invention provides a
package comprising the continuous tobacco slab or the multi-
layer structure of the invention. In the following the slab
and the multi-layer structure are referred to as the
Is "product". Such pack may be made of any suitable material or
combination of materials, including, for example but not
limited to carton, cardboard, metal or plastic. Preferably,
the package is a rigid pack which tightly encloses the
product. The rigid pack of the invention may be composed of
one, two or more parts. The pack has a pre-defined three-
dimensional shape which is selected such as to match and
support the final three-dimensional shape of the product. An
appropriate shape and sufficient rigidity of the pack are
essential to retain crucial product properties, including
shape, dimension and density of the tobacco product, in
particular the tobacco slab. This means that the packaged
product should substantially retain its shape, dimension and
density during all further manipulation until consumption
including transportation and storage. For example, a
cardboard pack with a grammage of between about 220 g/m2 and
300 g/m2 is sufficiently rigid. Advantageously, one or more
of the pack surfaces facing the tobacco product are partially
or fully coated with a material which is approved for use
with food and suitable to reduce or minimize friction upon
removal or insertion of the product. Furthermore, the package
will support the freshness of the tobacco product and prevent
its drying out. Particularly preferred is a pack made of
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cardboard whose inner surfaces are completely coated with
aluminum foil.
While size and shape of the pack may be such to
accommodate more than one tobacco product, preferred is a
pack containing one piece of product.
A preferred pack of the invention is a slide and shell
type pack which comprises an inner sleeve and an outer
sleeve. The inner sleeve directly circumscribes or encloses
the tobacco product. Preferably, the inner sleeve is
lo designed such that it covers four outer surfaces of the
product including the two major outer surfaces of the
product, in particular its top, bottom, front and rear
surfaces. The front and rear surfaces are determined by the
product length. The two side surfaces of the product
(determined by the product width) are not covered by the
inner sleeve. Preferably, the outer sleeve is designed such
that it directly circumscribes the inner sleeve with the
tobacco product and covers the two product side surfaces
which are not covered by the inner sleeve. Preferably, the
outer sleeve covers the side surfaces determined by the
product width and the top and the bottom surfaces of the
inner sleeve. In use, the consumer removes the outer sleeve
by pushing the inner sleeve circumscribing the tobacco
product out of the outer sleeve. Preferably, the outer and
the inner sleeve are both made from rigid cardboard. If
desired, the inner surfaces of the sleeves, in particular the
inner surface of the inner sleeve, may be partially or
entirely coated with another material or metallized suitable
to reduce friction. Suitable coating materials are readily
known in the art and include those disclosed for use in
cigarette paper tubes. A particularly preferred pack
according to the invention is a slide and shell pack wherein
the inner and outer sleeves are made of aluminum laminated
cardboard with a total grammage in the range of between about
220 g/m2 and about 300 g/m2, for example with a total
grammage of 275 g/m2 (250 g/m2 for the cardboard; 25 g/m2
aluminum foil). Reduction of friction facilitates the removal
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of the outer sleeve or pushing the tobacco product out of the
inner sleeve without breakage. Preferably the dimensions of
the inner sleeve correspond to the desired product
dimensions. Optionally, the package may comprise an inner
frame.
Advantageously, the package further comprises an outer
wrapper to preserve freshness of the tobacco product and
prevent drying out. Suitable wrappers are known in the
industry and include wrappers from materials which are
lo currently used to wrap cigarette packs or cartons, such as
polypropylene. The outer wrapper may include means
facilitating its removal, such as a tear tape.
In yet another aspect, the present invention provides a
container designed to hold several, for example up to ten,
Is packs comprising a tobacco product according to the present
invention.
To make his own cigarettes starting from a continuous
tobacco product of the invention, the consumer may use a
cigarette making device to facilitate transferring a suitably
20 sized piece of the slab or the multi-layer structure into a
pre-made cigarette tube. Optionally, such tube comprises a
filter, preferably a ventilated filter.
For example, a device suitable for use with the tobacco
slab or multilayer structure according to the present
25 invention comprises a portioning means, a separating means
such as a knife suitable to separate a portion of tobacco
from the slab or multi-layer structure, a transportation
means to move the slab or multilayer structure towards the
separating means by a defined distance and a filling means to
30 fill the portion into the pre-made cigarette tube. During
this procedure the making device, the pack or both support
the integrity of the tobacco slab or multi-layer structure
during the process. Advantageously, the pack comprising the
tobacco product is inserted in the cigarette making device.
35 In use, the tobacco product is moved out of the pack portion
by portion. Since the tobacco slab according to the invention
has a substantially uniform tobacco density across the whole
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volume of the block, each portion of the same size contains
substantially the same amount of tobacco.
Embodiments of the invention will now be described, by
way of example only, and with reference to the accompanying
drawings, in which:
Figure 1 shows a continuous tobacco slab 10 consisting
of one layer of cut filler;
Figure 2 shows a continuous three-layer sandwich
structure 20 wherein the base layer 12 and the top layer 14
each are a sheet of reconstituted tobacco, and the middle
layer is a tobacco slab 10 of cut filler.
The continuous tobacco slab 10 in Figure 1 shows a
continuous tobacco slab 10 of the invention consisting of a
single layer of cut filler. The slab 10 has a width of 73
mm, a height of 8 mm and a length of 140 mm. It is made of
24 g of cut filler and has an average filling density of
about 235 mg/cm3. The slab may yield at least 30 cigarettes.
The cutting width of the cut filler is 0.65 mm.
The continuous sandwich structure 20 in Figure 2 has
three layers and consists of a 0.5 mm base layer 12 made of
top loaded reconstituted tobacco sheet, a 9 mm tobacco slab
10 made of cut filler and a 0.5 mm top layer 14 of top
loaded reconstituted tobacco sheet. The cut filler top loads
of the base layer 12 and the top layer 14 each face towards
the tobacco slab 10 comprising the cut filler middle layer
10. The weight of the structure is 24 g, the average density
is about 240 mg/cm3.
